http://excya6cvdfpgspsf57w42mvyd5mzthi34l6eopqkhxg67y7wp6qry6qd.onion/verify-an-email-address-on-facebook.html
Once you accessed, you will see the profile URL in your browser. Something like this: In the example obove, the URL is: https://www.facebook.com/charles.black55 , so the profile's username is: charles.black55 Sometimes, the URL can be longer, because it can include some others parameters.